Six-Ports

Paper appearing in The Proceedings of Microwave Update 2011. It's about the basics of six-port theory, with an explanation of six-ports as modulator and demodulator.

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Greetings MEPsters,Today I was able to configure two WRT54GLs running OpenWRT. One was an access point with a wired connection to the internet, and the other was configured as a bridge. Beagleboards were attached to both of the WRT54GLs, and I could ping from both of them.Here is a whiteboard block diagram of how these routers are configured.http://www.flickr.com/photos/w5nyv/4332411901/If that's too small (sorry about the white balance) then try this larger image.http://www.flickr.com/photos/w5nyv/4332411901/sizes/l/Today, I watched a webinar about High-Speed Multimedia Webinar. I noticed the webinar at the last minute - otherwise I would have mentioned it earlier.Here's the writeup about it.-=-=-=-=-=-=-=-HSMM-MESH(tm) Networking SeminarThe HSMM-MESH(tm) Networking Seminar will cover all aspects of the HSMM-MESHsoftware developed in Austin, TX. The Webinar will begin with an explanation ofHigh-Speed Multi-Media (HSMM) and the subset of this topic which uses modifiedLinksys WRT54GL 2.4 GHz Wireless Routers to form a mesh network, handy for highspeed digital communications in the ham band - for emergencies, special eventsand field day.The Webinar will cover applications, antennas, hardware, and the software. Youwill learn how to load the software and how to configure it.In the second part there will be a lab where we will actually load the softwareinto a router and configure the router. You will need a Linksys WRT54GL (anyversion) or a WRT54G (Version 1.1 through 4 - version 5 or higherwill NOT work.)The Webinar will be online at 8:00am Central time to give you a chance to getlogged in and test your setup before something starts happening. Trainingstarts at 9:00am with 10 minute breaks about every hour. And we will finishin the afternoon after a lunch break.You should Register before Saturday morning if possible. . If you have amicrophone and headset you will be able to ask questions verbally over VOIP.Otherwise you can type in questions to be able to interact with the speaker.The Webinar is provided through the courtesy of Ham-Com and is presented bymembers of the NTMS-HSMM and Austin-HSMM groups. (contact...@kdream.com) hsmm-mesh.org-=-=-=-=-=-=-=-There was a third part. Some of the third part was recorded by Jordan Cronin, and those recordings (he warned the quality might not be as good as he would like) can be found here:http://qik.com/jordancroninThe seminar introduced HSMM and gave specific examples of its use in public service events. The configuration of their specific build of OpenWRT followed.Read more about HSMM-MESH here:http://www.hsmm-mesh.org/For our application, I think there is a wrinkle with the HSMM-MESH software. On the hsmm-mesh site, I read the following passage."One feature of OLSR is called the "dynamic default gateway". When a node has internet access, as verified by periodic pings of various internet servers, it tells its neighbors that internet is available and the surrounding nodes will use this node as its default gateway. This is how every node gains internet access even if only one of them is connected to the internet. It still works if multiple nodes have direct internet access, but its behavior in this mode is not well tested. Sporadic internet access such as web browsing should handle this well. However, connections intended to be continuous, like streaming media, will definitely come to a halt if internet access switches from one node to another. This is because the IP address that you are accessing the internet from just changed and the far end will close the connection, as it should."This sounds like that video... HSMM report 6 Feb 2010
Hello everyone!We're putting two Rev B beagleboards together with Linksys routers (WRT54GLs running OpenWRT) and experimenting with that combination for mobile MEPs. This is 2.4 GHz instead of our desired 3.4/5.8GHz full duplex plan, but will allow for easier and cheaper development of the software on the TI OMAP. This is much closer to the HSMM model of MEP than the custom-hardware model of MEP. While some progress has been made on hardware, I'd like to experiment with a solution that is more off-the-shelf. For one thing, the cost is quite competitive. A WRT54GL is $60. A Beagleboard is #149. USB to Ethernet conversion cable ranges in price from $10 to $25, depending on speed.USB is not the best interface for our application, but it is the interface available on a stock beagleboard. However, there is an improvement available. The BeagleBuddy Zippy Ethernet Combo Board is an $80 expansion board for the BeagleBoard that adds the following: * Battery Backed RTC * Second MMC slot * 10BaseT Ethernet * Second RS-232 * +5V level I2C * AT24 EEPROMThis eliminates USB in the path to the router. We have one Zippy board here at the lab, currently used on a project to set up a spectrum survey for 70cm.Revision 5 of the test code tutorial for the NEON processor was released, and this revision is a candidate for the final version of the document. It can be found here:http://www.delmarnorth.com/microwave/requirements/testcodetutorial_neon-test_draft5.pdfIt's also in the RSS feed, so it will automagically appear in your feed reader if you have subscribed to the project feed.Next step is to add NEON support to Fastest Fourier Tranform in the West library. This project will improve signal processing on the beagleboard.For further reading and reference, here are some web pages for the devices and software mentioned today.Fastest Fourier Tranform in the West: http://www.fftw.org/BeagleBuddy Zippy: http://www.tincantools.com/product.php?productid=16147&cat=249&page=1Beagleboard Home Page: http://beagleboard.org/WRT54GL router: http://en.wikipedia.org/wiki/Linksys_WRT54G_series#WRT54GLOpenWRT: http://www.openwrt.org/More soon,-Michelle W5NYV Weekly Report 1 Feb 2010 - 5 Feb 2010
Here is draft 5 of the neon test code tutorial, for review and critique. Neon-test Test Code Tutorial Draft 5
Neon-test Test Code Tutorial Draft 4
This is a tutorial on a suite of test code called neon-test from Philip Balister. This is intended to be a tutorial on the NEON processor-specific instruction set in order to bring people interested in coding for NEON more quickly up to speed. Comment and critique are welcomed and encouraged. neon-test Test Code Tutorial Draft 2
Draft presentation for the SDR Forum at Dayton 2009. Slides + notes. Not everything in the presentation will be on the screen, but the presentation (drafts and final version) will include complete notes. Draft Presentation for SDR Forum at Dayton 2009
Tuesday Challenge for 14 April 2009 was:I'm interested in reasons *not* to select Android as a baseline OS for MEP stations.Here are a few more details:Android is an open‐source operating system primarily intended for cellular phones.www.android.comAndroid scales to systems like MEP, third party development is encouraged, it's supported by a consortium of all sorts of people we've heard of (http://www.openhandsetalliance.com/), and it uses lots of linux‐like process protection protocols that would seem to enhance stability and usefulness. People seem interested in developing for Android, and it might help MEP greatly to go in this direction. What do you all think?I have an image for the TI OMAP from the Embedded Systems Conference, and would love to hear from anyone else pro or con on Android.Philip Balister, Assi Friedman, Eric Fort, Bob McGwier, Paul Williamson, Roger Thompson, Ken Easton and Frank Brickle contributed to the discussion of the consideration of Android for MEP.Thank you to all the participants in and followers of the discussion so far.The consensus was a well‐reasoned preference for embedded linux over Android, primarily due to the insular nature of Android (Android is based on linux but it is not linux) and also due to the fact that it is at this time an unproven platform that may not be as flexible as we need for MEP.The potential advantages of Android are significant, and space will be made in the software section of the page for anyone that would like to branch off and pursue Android for MEP. However, the primary effort will be in the direction of embedded linux. Both Moblin (mobile linux http://moblin.org/) and QtExtended (http://qtopia.net/modules/devices/) were recommended for consideration.‐Michelle W5NYV Tuesday Challenge Summary
Greetings everyone! Here's a brief report for the past week or so. 1) Development Image News: While we didn't get the MEP-flavor Moblin development image finalized - the development tools are sitting on the desktop waiting for installation - we did complete the task of growing the virtual disk to a larger and more useful size (from 2GB to 8GB). The development image (Moblin V2) can be run in a virtual machine to develop Moblin applications. What you do is work within the "guest" operating system of Moblin, while running whatever operating system you prefer as the host. More details about Moblin can be found at www.moblin.org. 2) I have a set of ideas that need to get organized into a presentation for Dayton. First, I'm planning to present the work from uWSDR (the transmit modulator project organized by Grant Hodgson. I will endeavor to do the work of his team justice in the talk. The second thing I want to communicate is ideas shared with and by Frank Brickle, about the status of microwave SDR in general as the "place we want to go", and how MEP incorporates modern communications models. I would very much like to show performance comparisons between the traditional transverter approach and currently-designed or currently-buildable SDRs in bands specific to our project. Third, I will appeal for volunteers to help get more of the project into more active development. I'm aiming to have a draft of these ideas published over the weekend, and am very much interested in feedback and ideas for this presentation.3) I started work on a software specification for the discovery function. The reason I picked this one is because I believe I understand how to describe it, I'm confident that it's a reasonable starting point for software design participation, and it provides a way to experiment with different interpretations of what the MEP user interfaceshould be. More soon, -Michelle W5NYV Weekly Report 1 May 2009
Report for 8 December 2008 - 4 April 2009 Weekly Report 8 December 2008 - 4 April 2009
Test plan for the SBMS transverter. Applicability to MEP TBD. SBMS Transverter Test Plan
Tuesday Challenge 9 December 20081. In your opinion, what is the most interesting use case for a MEP station?2. What local oscillator scheme makes the most sense for a 3.4GHz, 5.6-8GHz duplex system? Tuesday Challenge for 9 December 2008
Plans for this week: 8 December – 12 December 20081. Complete revision 5 of the Station Discovery Document. (carried over from last week)2. Release revision 0.3 of the MEP Air Interface.3. Expect the first transverter boards from the San Bernardino Microwave Society to arrive. Update list with communications with designer.4. Learn more about the ARCHES project.5. Check in with uWSDR project and see how GEMMA is doing.6. Design MEP logo, Team Air Interface badge, and Baseband badge.Welcome to the Microwave Engineering Project development email list! Thanks for joining.Please forward this email to anyone you think would be interested in the development of the project.Send updates and work proposals to w5nyv@yahoo.comSign up for this list athttp://lists.uppermeadow.com/mailman/listinfo/mep-devOur project webpage is located athttp://www.delmarnorth.com/microwaveThere is a podcast that you can subscribe to. This will deliver project documents, audio, and video to you so that you do not have to go check the website for them. They will appear in the feed reader of your choice. Weekly Plan 8 December - 12 December 2008
System model, layering, and protocol discussions. Version 0.2 published on 8 December 2008 Air Interface Document version 0.2
MEP Weekly Report for 1 December – 7 December 2008The beginning of the Air Interface document was published with more to follow.Work continued on the 5th revision of the Station Discovery Document.Discussions about MEP as an IP network, MEP as a layer 2 network, and MEP asbuilt from WiFi components occurred. The diagram in the PDF is an attempt tosummarize the main points.We learned about the ARCHES project through Glenn Currie KD5MFW.We discussed DTN and whether and how it might fit in to MEP. Weekly Report 1 December - 7 December 2008
Posted for review on 2 December 2008. MEP Air Interface revision 0.1
Plans for this week: 1 December – 5 December 20081. Complete revision 5 of the Station Discovery Document.2. Release revision 1 of the MEP Air Interface.Welcome to the Microwave Engineering Project development email list! Thanks for joining.Please forward this email to anyone you think would be interested in the development of theproject.Send updates and work proposals to w5nyv@yahoo.comSign up for this list athttp://lists.uppermeadow.com/mailman/listinfo/mep-devOur project webpage is located athttp://www.delmarnorth.com/microwaveThere is a podcast that you can subscribe to. This will deliver project documents, audio, andvideo to you so that you do not have to go check the website for them. They will appear in thefeed reader of your choice. Weekly Plan 1 December - 5 December 2008
Station Discovery article for TAPR's newsletter PSR
An announcement and description of the current phase of the MEP project, which is Exploratory. This version includes the publication history. Exploratory Phase Announcement
Posted for review, comment, critique on 13 November 2008. Discovery Document Version 2
Version 2.0 corrected. MEP Beamwidth Notes version 2.0
Notes for the Discovery Document. This shows the half-power (3dB) beamwidth for a half-meter dish antenna across the frequency bands (3.4GHz to 6GHz) of interest to MEP. Half Power Beamwidth Notes

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Microwave Engineering Project
8/28/2011

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